The White House Conference on Aging (1971) has recently focused much attention on the nutritional needs of the elderly, citing impairment of taste and smell as one of the major factors leading to an inadequate diet. Research done during the first year on this grant indicates a substantial loss in food recognition by the aged. The proposed research is aimed at further investigating the sensory qualities of gustation and olfaction especially as they change during the aging process. First, food substances, spices, and essential nutrients will be ordered by multidimensional scaling procedures on the basis of their tastes and smells. It is virtually impossible to order most food substances (e.g. roast beef), spices, and nutrients by phenomenological means into the traditional gustatory categories of sweet, sour, salty, and bitter. Three groups of subjects will be used in these experiments: preadolescent, adult, and elderly. At the very least, the methodology of multidimensional scaling, as applied here, will yield multidimensional spaces which illustrate meaningful relationships and distances among food stimuli revealing how these relationships change with age. It will also deepen our understanding of both the psychological and physical dimensions underlying the experience of taste and smell. Second, thresholds for essential nutrients will be found as well.